Process of producing an incendiary composition



PROCESS OF PRODUCING AN INCENDIARY COB POSITION Morris S. Kharasch,Chicago, Ill., assignor to the United States of America as representedby the Secretary of War No Drawing. Application December 30, 1943 SerialNo. 516,313

3 Claims. (CI. 52-23) there was little likelihood of using such acompound directly as an incendiary agent, because in the first placesuch substances are highly volatile, and in the second place theyquickly absorb oxygen to form peroxides which explode violently on theslightest touch. However, I have discovered that polymerized derivativesof acetylenes have properties which adapt them for use as incendiaryagents.

An object of this invention is to utilize suitably stable polymers ofacetylenes including copolymers, particularly polymers of divinylacetylene and the like, as incendiary agents.

Another object of this invention is to provide a process for formingsolid incendiary materials comprising polymers of acetylenes.

A further object of this invention is to provide useful warfaremunitions comprising incendiary agents in which suitable polymers ofacetylenes are utilized.

It has now been found that there are derivatives of acetylene,particularly vinyl acetylenes, which are very suitable for use asincendiary agents. One of these derivatives is polymerized divinylacetylene. This substance which comprises principally the trimer withsome tetramer can be available in fairly large quantities as anindustrial by-product. It has been commercially sold as an 80% solutionin toluene or xylene. It is used as an acid-proof coating for materials.This material, when properly handled, is not unduly hazardous. It doesnot ignite too readily and burns with a smoky flame. Nevertheless, ithas been possible to adopt this substance as an organic component of avery effective incendiary material which has proved to be ofconsiderable interest as fillers for grenades.

The incendiary substances containing polymers may also be used to filllarge incendiary munitions, such as bombs; and they have proved to beuseful as binders for propellants.

There are two types of grenades or hand incendiaries in which theacetylenic polymer incendiary compositions have been found to be veryeffective. They are paper tubes and magnesium tubes with the incendiaryagent compressed therein. In both types, a button of matchheadcomposition was attached to one end of the tube, this end being closedwith a removable cap coated with a friction material. The finishedincendiary resembled in outward appearance a shortened railway fuze. Itwas easily ignited by striking the match-head with the removable cap.Hand incendiaries of this type with total weights of 90 to 250 gramswere subjected to tests. The sizes mentioned are arbitrary, for tubes ofany size can be filled with the incendiary agent.

The distinguishing characteristics of these incendiaries are as follows:they burn with a vigorous torch-like flame which extends a foot or morefrom the mouth of the tube. The burning polymer incendiary agent ignitesmagnesium; and when magnesium tubes are used, much longer flames areoften obtained during the time when the polymer incendiary agent andmagnesium are burning simultaneously.

The polymer incendiaries were tested on wooden attictype structures. Inall instances, they were at least as effective as any other type ofincendiary tested in producing sustaining fires; i.e., fires which causecomplete confiagration of a structure.

If the incendiary tubes or containers for the acetylene polymer agentare coated on the outside with paraffin, they may be soaked for severalhours in water without impairing either their ignition or their burningproperties.

In comparison with'hand incendiaries using thickened kerosene inCelluloid containers, acetylenic polymer incendiaries have the followingadvantages: they are hard tubes filled with a solid; hence, they cannotbe crushed readily and contain no liquid to escape from a damagedcontainer. As long as the igniting agent or match-head composition isnot exposed, it is almost impossible to Example A mixture is prepared tocontain about 30% of an solution of divinyl acetylene polymer in anaromatic hydrocarbon, about 10% heavy petroleum oil and about 60% crudesodium nitrate; and the liquid divinyl acetylene polymer is then furtherpolymerized by heating the mass to C. in air forabout 16 hours. A solidmass thus formed is rolled to produce a uniform granular material. Theproduct is stable and can at any time be loaded into tubes, for example,using a pressure of about 2,000 lbs. per square inch.

For a given acetylene polymer mixture, the burning time of theincendiaries thus prepared is proportional to the length of the tubeand, Within wide limits, dependent on the cross section. The burningrate varies somewhat with the quantity of heavy oil used and with themesh and nature of the oxidizing salt; of these, the latter is the moreimportant. By controlling these factors, there have been prepared 7-inchincendiaries having combustion periods varying from about 1 /2 to 6minutes.

The magnesium tubing used in some of the hand incendiaries submitted fortest had a wall thickness of inch. Each tube was one inch in diameterand 6 /2 inches long; the filled tubes weighed about grams. Thepolymerized acetylene agent burned for about 1 to 1 /2 minutes beforethe magnesium tubing ignited. The magnesium andthe filling then burnedtogether, and a vigorous burning of the magnesium took place in lessthan another minute. There was further burning which lasted for severalminutes. It was found possible to vary, under wide limits, the timebefore the ignition of the magnesium casing and the time during whichthis casing burns vigorously, particularly by varying the mesh of thenitrate and the type of the oxidizing agent. For maximum effect, it isadvantageous to have the magnesium burn rapidly.

addition products.

The polymerized acetylen'es may be usedin mixtures and in conjunctionwith other incendiary agents, such as thickened gasoline, Thermit typeagents, phosphorus, granular magnesium and the like. They 'may-be usedwith various types of oxidizing agents, stabilizing agents, also withstarting and igniting agents generally employed for incendiaries.

It is to be understood that the invention is not to be limited by thespecific illustrative examples and'that' modifications come within thespirit and scope of the invention. I claim: V 1. A process for producingan incendiary material granular mixture is finally compressed bycomprising preparing a mixture of about of an solution of the polymer ofdivinyl acetylene in an aromatic hydrocarbon, about 10% heavy mineraloil and about 60% sodium nitrate, exposing said mixture to air until asolid mass adapted to be crumbled is formed, and then rolling said mass,until the mixture is uniformly granulated;

2. The processof claim 1 in which the temperature i of the air ismaintained at approximately C.

3. The process of claim l in which said air is maintained at atemperatureof approximately 85 C. and the a pressure of about 2000# persquare inch. 7

References Cited in'the file of this patent V UNITED" STATES PATENTS1,361,286 Patrick Dec. 7, 1920 1,436,248 Hammond Nov. 21, 1922 1,812,541Nieuwland' June 30, 1931 1 ,896,162 Carter Feb. 7, 1933 2,294,415McBride Sept. 1, 1942 2,329,522 Duncan "Sept. 14, 1943 FOREIGN' PATENTS127,050 Great Britain May 29, 1919

1. A PROCESS FOR PRODUCING AN INCENDIARY MATERIAL COMPRISING PREPARING AMIXTURE OF ABOUT 30% OF AN 80% SOLUTION OF THE POLYMER OF DIVINYLACETYLENE IN AN AROMATIC HYDROCARBON, ABOUT 10% HEAVY MINERAL OIL ANDABOUT 60% SODUIM NITRATE, EXPOSING SAID MIXTURE TO AIR UNTIL A SOLIDMASS ADAPTED TO BE CRUMPLED IS FORMED, AND THEN ROLLING SAID MASS, UNTILTHE MIXTURE IS UNIFORMLY GRANULATED.